1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device. More particularly, the present invention related to a method of inspecting a bonding state between a liquid crystal display panel and a drive IC and a structure enabling easy checking of a pressed state of conduct balls of anisotropic conductive film electrically connecting a pad part and a drive IC of a liquid crystal panel.
2. Description of the Background Art
Liquid crystal displays (LCDs) are becoming lighter and thinner, they can operate with relatively low power consumption, and their picture quality continues to improve with enhancements of liquid crystal materials and development of fine pixel processing techniques. As such, LCDs have a wide variety of applications and their use continues to expand.
An LCD can be divided into a liquid crystal panel and a drive IC. The liquid crystal panel includes liquid crystal cells arranged in a matrix form between two sheets of glass substrates (namely, an upper glass and a lower glass), and switching devices (namely, a TFT array) for switching signals supplied to the liquid crystal cells. The drive IC is mounted on a printed circuit board (PCB) and drives the liquid crystal panel.
A TCP (Tape Carrier Package) is used to transfer a signal between the liquid crystal panel and the PCB. The TCP is directly attached to the lower glass and the printed circuit board by using a conductive resin such as an anisotropic conductive film (ACF) or the like. In this case, the ACF includes conductive balls having conductivity.
When the TCP is pressed with a certain pressure so as to be attached to an attachment portion (namely, a contact portion between the TCP and the lower glass or between the TCP and the PCB), the conductive balls in the ACF provides conductivity between the two attached surfaces. In this respect, however, when the conductive balls are pressed, if they fail to be pressed adequately to a state suitable for signal transmission, a distortion occurs in signal transmissions.
In a related art, in order to monitor the pressed state of the conductive balls, a measurement unit is used, or the pressed state is visually checked by the naked eye by using pressurization paper. Thus, the expense is increased according to employing the measurement unit, and/or the fabrication process is delayed due to the additional process of checking the state of the conductive balls by using the pressurization paper.